Ubuntu 11.04 is dubbed Natty Narwhal, it will be the fourteen release of the Ubuntu operating system, and it will see the light of day on April 28th, 2011.

Ubuntu is a Linux distribution for your desktop or server, with a fast and easy install, regular releases, a tight selection of excellent packages installed by default, every other package you can imagine available from the network, and professional technical support from Canonical Ltd and hundreds of other companies around the world.

http://www.ubuntu.com/